An anatomical basis for primary acquired nasolacrimal duct obstruction
S. A. Groessl, B. S. Sires and B. N. Lemke
Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, USA.
OBJECTIVE: To measure any sex size differences in the bony nasolacrimal
drainage systems in a normal, age-matched population. METHODS: A
retrospective study of axial cut maxillofacial computed tomographic scans
was conducted. Three levels of the bony nasolacrimal duct (NLD) system on
the right and left sides were measured along the anteroposterior diameter.
The data were analyzed using 2-tail t test, analysis of variance, and
linear regression methods. RESULTS: Scans from 71 adult patients (36 men
and 35 women) were reviewed. Women were found to have a smaller bony
diameter at the level of the lower fossa (P = .01) and the middle NLD (P =
.06) compared with those of men. The adult inferior bony fossa increased in
size with age in both men and women, while the middle NLD increased in size
in men only. No significant size difference was found between the right and
left side at any level. CONCLUSIONS: Size differences are found in
measurements of bony nasolacrimal excretory systems in men vs women. Women
have significantly smaller dimensions in the lower nasolacrimal fossa and
the middle NLD. The anteroposterior dimension of the bony nasolacrimal
canal at the fossa level enlarged in both sexes, with age co-inciding with
osteoporotic changes throughout the body. These quantitative anatomical
observations provide a contributory factor to explain the increased
prevalence of primary acquired NLD obstruction in women.
